Collector apparatus

ABSTRACT

An industrial heavy-duty vacuum collector suitable for use with waste material hoppers, particularly dump hoppers. The collector includes a positive displacement vacuum blower apparatus, a material separator apparatus on a base mountable in airtight relation with the hoppers and an automatic control apparatus for the collector.

I United States. Patent 1191 Dupre et a1.

[ Dec. 25, 1973 COLLECTOR APPARATUS [75] Inventors: George T. Dupre,Palatine; Thomas M. DeMarco, Chicago, both of 111.

[73] Assignee: National Foundry Equipment Company, Inc., Palatine, 111.

221 Filed: Jan.12, 1973 21 A 1.1 16.=323,0ss'

Related US. Application Data [63] Continuation of Ser; No. 109,246, Jan.25, 1971,

abandoned.

[52] US. Cl. 55/337, 15/352, 55/17, 55/215, 55/305, 55/334, 55/341,55/356,

55/366, 55/423, 55/425, 55/429, 55/432, 55/449 [51] Int. Cl B0ld 50/00[58] Field of Search 15/301, 314, 352; 55/211, 215, 304-305, 312, 315,318, 337,

[56] References Cited UNITED STATES PATENTS 3,320,727 5/1967 Farley etal 55/429 X 3,608,283 9/1971 HuglO 15/352 x 2,372,316 3/1945 Curtis.....55/17 ux 3,541,631 11/1970 Kluge et al 15/352 X 3,650,420 3/1972Mahane'y 141/312 x 3,554,520 1/1971 Grosko 141/312 X 3,485,671 12/1969Stephens.... 55/429 ux 485,915 11/1892 Duckham... 55/17 3,577,705 5 1971Sharlit... 55/465 x 2,276,805 3 1942 Tolman 55/288 2,496,180 1 1950Smith et al 55/215 3,717,901 2 1973 Johnstone 55 429 x PrimaryExaminer-Frank W. Lutter Assistant ExaminerVincent Gifford Att0rney-NateF. Scarpelli [5 7 ABSTRACT An industrial heavy-duty vacuum collectorsuitable for use with waste material hoppers, particularly dump hoppers.The collector includes a positive displacement vacuum blower apparatus,a material separator apparatus on a base mountable in airtight relationwith the hoppers and an automatic control apparatus for the collector.

11 Claims, 5 Drawing Figures PATENTED UECZS 1973 sum 1 or 3 FIG.|

INVENTORS GEORGE r DUPRE' ATTORNEYS I THOMAS M. OEMARCO 050' 5:9PATENTED 2 15 3,780,502

FIGS

INVENTORS GEORGE r. DUPRE' "warms M. [EMA/v00 A! TORNEYS PATENTED Sum 3BF 3 3.780.502

II II |NVENTORS GEO/P65 r. DUPRE r MAS M. DEM RCO M ATTORNEYS COLLECTORAPPARATUS This is a continuation of application Ser. No. 109,246, FiledJan. 25, 1971, now abandoned.

BACKGROUND OF THE INVENTION This invention relates generally toimprovements in apparatus for collection of dust and other wet or dryparticulate waste and spillage materials at foundries and manufacturingplants and more particularly to a portable, heavy-duty, vacuum collectorapparatus suitable for use with standard waste material collectionhoppers, especially those of the dump hopper variety.

Operating procedures at foundries normally result in the accumulation ofwet and dry sand, often admixed with metal chips from castings and metalshop spillage from cast cleaning. Efficient foundry operation requiresremoval of those materials. Manufacturing plants also use grinders,pneumatic chisels, wire brushes, machining tools, and other power toolsand machines producing dust and particulate wastes. Such use gives riseto serious health, safety, and machine maintenance problems which canonly be eliminated through continuous removal of such wastes.

Various attempts have been made to provide vacuum collector apparatus toremove dust, sand and other materials of widely varying particulate sizeand weight at foundries and manufacturing plants. In some instances,permanent, centralized, heavy-duty, vacuum collector installations havebeen employed. These incorporate multiple collector hoses and conduitswhich extend from the vacuum source throughout the foundry ormanufacturing plant. While such permanent installations can generally beconstructed in a size capable of providing good vacuum strengthcharacteristics, the maintenance of the required extensive network ofairtight, obstruction-free conduits and hoses is both costly andinefficient.

Smaller, cannister-type or bag-type vacuum collectors have been employedas an alternative to the centralized installations described above. Suchsmall collectors are relatively portable, and their use does not entailthe maintenance of a network of hoses. Inherent size limitations,however, necessitate very frequent emptying of small collectors and therestriction of their use to collection of dry, fine particulate matter.Bagtype collectors are notably unsuitable for collection of wetmaterials due to the likelihood of clogging of the bag fabric.

No single collection apparatus heretofore devised has been suitable forindustrial use in terms of providing high vacuum strength, largecapacity and portability and effective collection of wet or drymaterials.

SU MMARY Q OF THE INVENTION The vacuum collector apparatus of thepresent invention provides high vacuum strength through use of heavyduty, positive displacement, vacuum blower apparatus. Through adaptationfor use in combination with standard waste material dump hoppers, theappa ratus of the invention provides for collection of large quantitiesof waste materials. Portability of the apparatus is provided throughadaptation for movement by fork lift equipment. Exceptionaleffectiveness in the collection of wet and dry materials is affordedthrough incorporation in the collector apparatus of a multistagematerial separator system.

The collector of the present invention generally comprises positivedisplacement vacuum blower apparatus and material separator apparatus ona portable base mountable in airtight relation upon standard waste ma?terial dump hoppers.

Preferred embodiments of the invention may include a cyclone-typematerial separator for separating out and exhausting large sizeparticulate matter, a particulate accelerator for separating out andexhausting small size particulate matter and moisture droplets, and amultiple, flat bag filter for collection of fine particulate matter.

Also included may be a blower exhaust muffler apparatus and automaticshut-off apparatus sensitive to the volume of material collected in thehopper.

Collector apparatus constructed according to the invention is suitablefor use in a variety of manners in order to meet the particularcollection requirements of a given foundry or plant. For example, thecollector may be moved from one dump hopper to another with the hopperslocated at various sites throughout a given facility; or the collector,in combination with a hopper upon which it is mounted, may be locatedand relocated as a unit throughout the facility. An alternative use ofthe collector would include mounting it in a semi-permanent fashion upona frame fitted with apparatus permitting repeated mounting anddismounting of the collector on one dump hopper after another, as suchare supplied to and removed from the collector. Another use of thecollector could include mounting it, either temporarily or permanently,on a large, permanent, bin-type hopper which would be periodicallyemptied.

The above-mentioned uses of the collector apparatus are facilitated byits adaptation for movement by forklift equipment. This is especiallyeconomically advantageous because expensive fork-lift equipment is oftenidle during normal clean-up periods at factories and foundries and hencenot otherwise put to its most efficient use at those times.

Further aspects and advantages of the present invention will be apparentfrom the following description of preferred embodiment thereof,reference being made to the following drawings.

BRIEF DESCRIPTION OF THE DRAWINGS F IG. 1 is an isometric view of anembodiment of the invention showing collector apparatus mounted on astandard dump hopper, with portions cut away.

FIG. 2 is an isometric view of an embodiment of the invention showingcollector apparatus mounted on a bin-type hopper, with sections cutaway.

FIG. 3 is a plan view of an embodiment of the invention.

FIG. 4 is a sectional view taken along lines 44 of FIG. 3; and

FIG. 5 is an expanded view of a portion of FIG. 4.

DESCRIPTION OF A PREFERRED EMBODIMENT FIG. 1 shows an embodiment 10, ofvacuum collector apparatus of the present invention mounted on a wastematerial dump hopper ll.

Hopper l 1, for use in combination with the collector, may be of aconstruction and capacity suited for the particular requirements of agiven foundry or plant. Many foundries, for example, presently use steelhoppers of 27 cubic foot capacity. Hopper 11 will ordinarily be fittedwith channels 12, 12 for receiving tines of fork-lift equipment.

Collector of the embodiment shown includes a platform base structure 13of a size accommodating mounting in airtight relation upon hopper 11.Base 13 is preferably constructed of heavy guage steel and is providedwith channels 14, 14 adapted to receive the tines of fork-liftequipment, accommodating movement thereby.

Mounted on base 13 is an electric motor 15 and a blower 16 whichprovides the vacuum source for material separator apparatus 17. Motor 15and blower 16 may be of standard construction with a preferred motorsize for most industrial purposes being about 25 horsepower, permittingdevelopment of about a 20 inch Hg vacuum. Size specifications are, ofcourse, subject to wide variation, depending upon the particulate sizeand weight characteristics of the materials to be collected. Blower 16is ordinarily connected to motor 15 by means of pulley sheaves 15a, 16a,and endless belts 15b.

Collector 10 also includes an intake tube 18, a blower exhaust muffler19, and an automatic shut-off control apparatus 20 (FIG. 4). Automaticshut-off control 20 preferably includes a plunger switch element 20awhich operates to turnoff motor 15 when hopper 11 becomes filled withwaste material.

Platform base 13 is provided with agasket 21, by means of which anairtight relation is maintained between collector 10 and hopper l1.Gasket 21 is preferably constructed of gum rubber, neoprene,polyethylene, or other such resilient material. While it is mostadvantageous that a single gasket 21 be mounted on platform base 13,gaskets may be fitted on each dump hopper 11.

Platform base 13 may thus be mounted on a standing dump hopper l1 andmoved from one hopper to another, or may be mounted in a semi-permanentmanner as shown, with platform support flanges 22 supported onexpandable and collapsible pneumatic bellows 23 resting on support frameelements 24 of a support base plate 25. Base plate 25 may be wheelmounted, if desired, to facilitate movement of the collector and frameas a unit without fork-lift equipment.

When pneumatic bellows 23 are expanded (as indicated in phantom lines at230 in FIG. 1), the collector 10 is in a raised position; and an emptyhopper 11 may be set in place below it. Bellows 23 may then becollapsed, lowering collector 10 to an airtight position on hopper 11with gasket 21 abutting flange 26 of the hopper.

Upon filling of hopper 1 l with collected waste material, collector 10may again be raised to permit removal and replacement of the hopper.

If suitable for the particular purposes of the user, the automaticshut-off control 20 may be electrically connected with apparatusoperating the pneumatic bellows 23 to effect automatic raising ofcollector 10 after filling of hopper 11 and shut-off of motor 15.

Operation of blower 16 develops a vacuum in conduit 27 leading tomaterial separator apparatus 17 including cyclone separator 28.Evacuation of separator apparatus 17 develops a vacuum in hopper 11 andcauses a suction at intake tube 18.

Operation of material separator apparatus 17 may be understood throughconsideration of FIGS. 2, 3 4 and 5.

For the purposes of the following discussion, the term particulatematter, will be understood to include both solid and liquid materials asopposed to air or other gaseous materials. Wet and dry particulatematerial drawn in through a hose (not shown) attached to intake tube 18will first be subjected to cyclonic separation from the airstream bycyclone separator 28.

Particulate material suspended in the airstream drawn in at intake 18 isimpacted along the curving walls of base cylinder 29 of cycloneseparator 28. According to well-known physical principles ofheterogeneous material flow, the heaviest of waste material particlesare separated from the flow of the airstream and tend to fall downwardin a cyclonic path into hopper 1 1 while the airstream is drawn upwardthrough cylinder 30 of cyclone separator 28 toward transverse chamberelement 31.

The airstream, carrying materials not removed by cyclone separator 28,thereafter is drawn from an upper transverse chamber 31 through avertically-extending linear accelerator nozzle 32.

Referring to FIG. 5, linear accelerator nozzle 32 may be of a generallyrectilinear configuration with rectangular broad side walls 33, 33 andnarrow end walls 34, 34 extending from transverse chamber 31 intoaccelerator ante-chamber 35 and defining an open-ended, prismicaccelerator passage 36 having an inlet 37 and an outlet 38.

As illustrated in FIG. 5 broad side walls 33, 33 may be provided withbeveled edge portions 330 adjacent outlet 38. Narrow end walls 34, 34may be similarly constructed.

Outlet 38 of nozzle 32 is centered directly above a rectangular orifice39 in an accelerator chamber ceiling plate 40.

In the course of passage through accelerator nozzle 32, particulatematerials in the airstream are accelerated and exit through nozzleoutlet 38 at a velocity greater than their initial velocity at nozzleinlet 37. Upon exiting outlet 33, accelerated materials travel throughaccelerator ante-chamber 35 and enter main accelerator chamber 41through the central portion of orifice 39.

The heaviest of the accelerated materials tend to continue in asubstantially straight downward path while the airstream backs up withinchamber 41 and exits at the edge portions of orifice 39 into antechamber35. Th path of airstream entering chamber 41 is thus generally downward,then lateral and finally upward. Typical paths of accelerated materialsand the airstream are respectively represented by dash-dot and dottedarrows in FIG. 5.

In operation, substantially the entire aristream will preferablydisperse laterally and turn upwardly before reaching the bottom quarterof accelerator chamber 41, leaving that space as a waste collection areawhich is substantially undisturbed by the airstream.

The shapes, relative dimensions and spacial arrangement of linearaccelerator nozzle 32, orifice 39 and main accelerator chamber 41 may besubject to design variations depending upon the proposed use of thecollector in which such elements are employed.

If, for example, wood shavings or other materials having a rather smallmass to volume ratio are to be collected, it may be advantageous toprovide a linear accelerator nozzle 32 having a substantiallycylindrical configuration to avoid clogging. In such a case, a circularorifice 39 would be accordingly provided.

If exceptionally finely divided wastes predominate in the materials tobe collected, the ratio of nozzle length to accelerator chamber lengthmay be adjusted to assure that chamber 41 is long enough to permitsubstantial turn around or back-up of the air-stream without disturbanceof wastes accelerated to the collection area at the bottom of thechamber. If, on the other hand, little or no such finely dividedmaterial is to be collected, a shorter chamber length may suffice forefficient operation.

Nozzle, orifice and chamber elements suitable for use in a collector 10,designed for collection of typical foundry wastes such as wet and drysand, gravel, shot and metal chips, would include a nozzle 32 having abroad side wall 33 with dimensions of 21 inches by four inches and anarrow end wall 34-with dimensions of one-fourth inch by four inches. Ahorizontal crosssection of passage 36 would accordingly be approximatelyone-fourth inch by 21 inches. A nozzle 32 of such dimensionswouldpreferably be centered with outlet 38 approximately one-half inchabove an orifice 39 which measured 21 1% inches by three-fourths inch. Asuitable main accelerator chamber would be prismic and measureapproximately 27 inches along chamber walls 41a, 41a parallel to thebroad side walls 33, 33 of nozzle 32 and approximately 12 inches alongthe walls 41b, 41b parallel to the narrow end walls 34, 34 of nozzle 32.A preferred height for main accelerator chamber 41 would beapproximately 48 inches.

At the base of accelerator chamber 41 is an outlet 42 having a closureflap element 43. Flap element 43 may be a counterweighted rigidstructure, as shown, or may be a simple flap of rubber or similarmaterial. Flap 43 is maintained in a position closing outlet 42 duringoperation of collector by the normal pressure differential betweenaccelerator chamber 41 and hopper 11. Once motor and blower 16 are shutoff, normal atmospheric pressure is restored to both chamber 41 andhopper l1 and the weigh-t of collected materials in chamber 41 willcause flap 43 to move downwardly, allowing exhaustion of collectedwastes from chamber 41 through outlet 42 into hopper 11.

The airstream leaving accelerator chamber 41 through orifice 39 is drawndown vertical channel 44 accelerator chamber 41, and thus do not remainto clog the bag fabric. I

From time to time materials trapped in the fabric of bag elements 46 maybe shaken loose through manual or automatic agitation. As indicated inFIGS. 3 and 4, automatic shaking of bag elements 46 may be effectedthrough use of an electric, reciprocating piston apparatus 50 having apiston element 51 attached to the bottom portions of bag elements 46.

Access to bag elements 46 may be had through a lidded port 52 in acasing 53 enclosing material separator apparatus 17. (FIG. 1)

Materials shaken free from bag elements 46 will ordinarily fall to thebase of filter chamber 45. At the base of chamber 45 is an outlet 54 anda closure flap 55 which function to exhaust waste from chamber 45 in thesame manner as the outlet 42 and flap 43 function and into filterchamber 45. Filter chamber 45 is preferably provided with apparatus forfiltering out and collecting substantially all remaining particulatematerial in the airstream.

Apparatus suitable for this purpose may include a plurality of fabric,flat bag, filter elements 46. Such filter elements generally comprise afabric bag on a frame. In operation, the airstream passes through thewalls of each bag toward its interior, leaving finely dividedparticulate material trapped in the fabric of the bag.

After passing through the bag walls, the airstream would be drawn upthrough slots 47 in a filter chamber ceiling plate 48 into an exhaustchamber 49 and thereafter through exhaust conduit 27 toward blower l6.Finally, the airstream would pass from blower 16 through conduit 19a toexhaust muffler l9 and into the air.

The effectiveness of fabric bag filter elements 46 is enhanced becausemoisture droplets are substantially separated from the airstreamupstream of the bags, in

with respect to accelerator chamber 41.

Filter chamber 45 may alternately be provided with filtering apparatus,other than bag elements 46, to perform a similar function. Suitablefiltering apparatus for this purpose may include porous air filterelements such as those used in automobile engines, air conditioners andthe like. Also suitable are filter devices of centrifugal, spin-off,electrostatic and hydraulic types.

In the operation of collector 10, wet or dry waste material willgradually fill hopper 11 until the material reaches the level of plunger20a of automatic shut-off control apparatus 20 (FIG. 4). As plunger 20ais contacted and displaced upward by waste material, a shutoff switch(not shown) is actuated to turn off motor 15. With motor 15 off, vacuumadherence of collector 10 to hopper 11 diminishes and collector 10 maybe separated from the hopper.

In addition to mounting on a portable hopper 11 as shown in FIG. 1,collector 10 of the present invention may be mounted in a mannerrepresented in FIG. 2, upon a permanently positioned collector bin 11a.Bin 11a would normally be provided with a discharge gate 11b for removalof collected waste materials from the bin. Gate 11b would, of course, beadapted for airtight closure to bin 11. Collector 10, so mounted, may beconnected to a plant-wide network of conduits and collector hoses, thusserving as a centralized collector for an entire facility.

Obviously, modifications and variations of the above described inventionmay be made without departing from the spirit and scope thereof.Therefore, only such limitations as are indicated in the appended claimsshall be placed thereon.

What is claimed is:

1. A portable, heavy-duty three stage vacuum collector for use with amaterial collection hopper in the sequential removal of heavier,residual, and most finely divided airbom particulate material from anairstream, said collector comprising:

a platform base;

means for mounting said base in airtight relation atop said materialcollection hopper;

blower means on said base;

a cyclone separator first stage mounted on said base,

said first stage including,

a. inlet and outlet ports for respectively receiving a stream of air andairbom particulate material, and withdrawing an exhaust stream of air,and

b. means, in open communication through said base, for substantiallyseparating said heavier particulate material from said stream anddirecting said heavier material toward said collection hopper;

a particulate material accelerator second stage mounted on said baseimmediately adjacent said cyclone separator first stage, said secondstage including,

a. a substantially vertically extending nozzle means having one endcommunicating with said outlet port for receiving said airstream andaccelerating said particulate material in said airstream,

b. chamber means vertically disposed below said nozzle means, forreceiving said airstream and particulate material accelerated by saidnozzle means,

c. orifice means at the top end of said chamber means, disposed beneathsaid nozzle means, for permitting entry into said chamber means fromsaid nozzle means of said airstream and particulate material acceleratedby said nozzle means, and permitting exit of said'air-stream from saidchamber means;

d. means at the bottom end of said chamber means,

in communication through said base, for substantially separating saidresidual particulate material from the exhaust stream of said cycloneseparator first stage and directing it toward said collection hopper,

e. closure means associated with said last recited separating anddirecting means,

f. means mounting said closure means for movement between an openposition, which permits passage of said separated residual particulatematerial into said collection hopper,- and a closed position in whichsuch passage is prevented, and

g. means, responsive to operation of said blower, for urging saidclosure means to said closed position when said blower is blowing and tosaid open position when said blower is not blowing;

a vertical channel having an upper end thereof for receiving saidairstream exiting from said orifice means, including means for directingsaid airstream downwardly within said vertical channel toward an exitbottom end thereof;

an air permeable particulate material-entrapping third stage mounted onsaid base immediately adjacent said particulate material acceleratorsecond stage, said third stage including,

a. an air filter chamber having a lower air inlet end and an upper airexhaust end; I

b. a filter element mounted in said filter chamber;

c. means communicating'said vertical chamber bottom end to the lower airinlet end of said filter chamber for receiving said airstream from saidvertical channel bottom and exit;

d. means at the bottom end of said filter chamber, in communicationthrough said base, for substantially separating the most finely dividedof said particulate material from the exhaust stream of said particulatematerial accelerator second stage and directing said separatedparticulate material toward said collection hopper;

e. closure means associated with said last-recited separating anddirecting means,

f. means mounting said closure means for movement between an openposition, which permits passage of said separated most finely dividedparticulate material into said collection hopper, and a closed positionin which such passage is prevented, and

g. means, responsive to operation of said blower, for urging saidclosure means to said closed position when said blower is blowing and tosaid open position when said blower is not blowing,

said blower means being in communication with said first, second andthird stages for drawing into said first stage a stream of air andairborn particulate material and exhausting from said third stage astream of air from which said particulate material has beensubstantially separated.

2. A collector as set forth in claim 1 wherein:

said means responsive to operation of said blower for urging saidclosure means of said accelerator second stage to said closed positioncomprises means responsive to an air pressure differential between saidcollection hopper and said accelerator second stage;

and said blower means further comprises means for developing saidpressure differential.

3. A collector as claimed in claim 2 wherein:

said means responsive to operation of said blower for urging saidclosure means of said particulate material-entrapping third stage tosaid closed position comprises means responsive to an air pressuredifferential between said collection hopper and said material-entrappingthird stage;

and said blower means further comprises means for developing saidpressure differential.

4. A collector as set forth in claim 1 wherein:

said means for mounting said base in airtight relation atop said hopperincludes means for raising and lowering said base.

5. A collector as set forth in claim 4, wherein:

said means for raising and lowering said base includes pneumaticallyinflating and deflating bellow means for raising said platform base awayfrom said hopper when said bellow means are inflated and for loweringsaid platform base toward said hopper when said bellow means aredeflated.

6. A collector as claimed in claim 1 wherein said platform base includeschannel means for receiving the tines of fork-lift equipment.

7. A collector as claimed in claim 1 wherein:

said vertical channel exit bottom end and said air filter chamber lowerinlet end include means for communicating the airstream at said lowerend of said vertical channel in a direction reversal flow fromdownwardly directly out of said channel to immediately upwardly as saidairstream is received into said air filter chamber.

8. A collector as set forth in claim 1 wherein:

said blower means includes positive displacement blower means.

9. A collector as set forth in claim 1 further including:

switch means for automatically shutting off said blower means upon thefilling of said hopper with collected particulate material.

10. A portable, heavy-duty three stage vacuum collector apparatus forthe sequential removal of heavier, residual, and most finely dividedairborn particulate material from an airstream, said collectorcomprising:

a platform base;

a material collection hopper;

means for mounting said base in airtight relation atop said materialcollection hopper;

blower means on said base;

a cyclone separator first stage mounted on said base,

said first stage including,

a. inlet and outlet ports for respectively receiving a stream of air andairborn particulate material, and withdrawing an exhaust stream of air,and

b. means, in open communication through said base, for substantiallyseparating said heavier particulate material from said stream anddirecting said heavier material into said collector hopper;

a particulate material accelerator second stage mounted on said baseimmediately adjacent said cyclone separator first stage, said secondstage including,

a. a vertically extending nozzle means having one end communicating withsaid outlet port for receiving said airstream and accelerating saidparticulate material in said airstream,

b. chamber means vertically disposed below said nozzle means, forreceiving said airstream and particulate material accelerated by saidnozzle means,

c. orifice means at'the top end of said chamber means, disposed beneathsaid nozzle means, for permitting entry into said chamber means fromsaid nozzle means of said airstream and particulate material acceleratedby said nozzle means, and permitting exit of said airstream from saidchamber means;

d. means at the bottom end of said chamber means,

in communication through said base, for substantially separating saidresidual particulate material from the exhaust stream of said cycloneseparator first stage and directing it toward said collection hopper,

e. closure means associated with said last recited separating anddirecting means,

f. means mounting said closure means for movement between an openposition, which permits passage of said separated residual particulatematerial into said collection hopper, and a closed position in whichsuch passage is prevented, and

g. means, responsive to operation of said blower, for urging saidclosure means to said closed position when said blower is blowing and tosaid open position when said blower is not blowing;

a vertical channel having an upper end thereof for receiving saidairstream exiting from said orifice means, including'means for directingsaid airstream downwardly within said vertical channel toward an exitbottom end thereof;

an air permeable particulate material-entrapping third stage mounted onsaid base immediately adjacent said particulate material acceleratorsecond stage, said third stage including,

a. an air filter chamber having a lower air inlet end and an upper airexhaust end;

b. a filter element mounted in said filter chamber;

c. means communicating said vertical chamber bottom end to the lower airinlet end of said filter chamber for receiving said airstream from saidvertical channel bottom end exit;

d. means at the bottom end of said filter chamber, in communicationthrough said base, for substantially separating the most finely dividedof said particulate material from the exhaust stream of said particulatematerial accelerator second stage and directing said separatedparticulate material toward said collection hopper;

e. closure means associated with said last-recited separating anddirecting means,

f. means mounting said closure means for movement between an openposition, which permits passage of said separated most finely dividedparticulate material into said collection hopper, and a closed positionin which such passage is prevented, and

g. means, responsive to operation of said blower, for urging saidclosure means to said closed position when said blower is blowing and tosaid open position when said blower is not blowing,

said blower means being in communication with said first, second andthird stages for drawing into said first stage a stream of air andairborn particulate material and exhausting from said third stage astream of air from which said particulate material has beensubstantially separated.

ll. Collector apparatus as set forth in claim 10 wherein said platformbase includes channel means for receiving the tines of fork-liftequipment.

1. A portable, heavy-duty three stage vacuum collector for use with amaterial collection hopper in the sequential removal of heavier,residual, and most finely divided airborn particulate material from anairstream, said collector comprising: a platform base; means formounting said base in airtight relation atop said material collectionhopper; blower means on said base; a cyclone separator first stagemounted on said base, said first stage including, a. inlet and outletports for respectively receiving a stream of air and airborn particulatematerial, and withdrawing an exhaust stream of air, and b. means, inopen communication through said base, for substantially separating saidheavier particulate material from said stream and directing said heaviermaterial toward said collection hopper; a particulate materialaccelerator second stage mounted on said base immediately adjacent saidcyclone separator first stage, said second stage including, a. asubstantially vertically extending nozzle means having one endcommunicating with said outlet port for receiving said airstream andaccelerating said particulate material in said airstream, b. chambermeans vertically disposed below said nozzle means, for receiving saidairstream and particulate material accelerated by said nozzle means, c.orifice means at the top end of said chamber means, disposed beneathsaid nozzle means, for permitting entry into said chamber means fromsaid nozzle means of said airstream and particulate material acceleratedby said nozzle means, and permitting exit of said air-stream from saidchamber means; d. means at the bottom end of said chamber means, incommunication through said base, for substantially separating saidresidual particulate material from the exhaust stream of said cycloneseparator first stage and directing it toward said collection hopper, e.closure means associated with said last recited separating and directingmeans, f. means mounting said closure means for movement between an openposition, which permits passage of said separated residual particulatematerial into said collection hopper, and a closed position in whichsuch passage is prevented, and g. means, responsive to operation of saidblower, for urging said closure means to said closed position when saidblower is blowing and to said open position when said blower is notblowing; a vertical channel having an upper end thereof for receivingsaid airstream exiting from said orifice means, including means fordirecting said airstream downwardly within said vertical channel towardan exit bottom end thereof; an air permeable particulatematerial-entrapping third stage mounted on said base immediatelyadjacent said particulate material accelerator second stage, said thirdstage including, a. an air filter chamber having a lower air inlet endand an upper air exhaust end; b. a filter element mounted in said filterchamber; c. means communicating said vertical chamber bottom end to thelower air inlet end of said filter chamber for receiving said airstreamfrom said vertical channel bottom and exit; d. means at the bottom endof said filter chamber, in communication through said base, forsubstantially separating the most finely divided of said particulatematerial from the exhaust stream of said particulate materialaccelerator second stage and directing said separated particulatematerial toward said collection hopper; e. closure means associated withsaid last-recited separating and dIrecting means, f. means mounting saidclosure means for movement between an open position, which permitspassage of said separated most finely divided particulate material intosaid collection hopper, and a closed position in which such passage isprevented, and g. means, responsive to operation of said blower, forurging said closure means to said closed position when said blower isblowing and to said open position when said blower is not blowing, saidblower means being in communication with said first, second and thirdstages for drawing into said first stage a stream of air and airbornparticulate material and exhausting from said third stage a stream ofair from which said particulate material has been substantiallyseparated.
 2. A collector as set forth in claim 1 wherein: said meansresponsive to operation of said blower for urging said closure means ofsaid accelerator second stage to said closed position comprises meansresponsive to an air pressure differential between said collectionhopper and said accelerator second stage; and said blower means furthercomprises means for developing said pressure differential.
 3. Acollector as claimed in claim 2 wherein: said means responsive tooperation of said blower for urging said closure means of saidparticulate material-entrapping third stage to said closed positioncomprises means responsive to an air pressure differential between saidcollection hopper and said material-entrapping third stage; and saidblower means further comprises means for developing said pressuredifferential.
 4. A collector as set forth in claim 1 wherein: said meansfor mounting said base in airtight relation atop said hopper includesmeans for raising and lowering said base.
 5. A collector as set forth inclaim 4, wherein: said means for raising and lowering said base includespneumatically inflating and deflating bellow means for raising saidplatform base away from said hopper when said bellow means are inflatedand for lowering said platform base toward said hopper when said bellowmeans are deflated.
 6. A collector as claimed in claim 1 wherein saidplatform base includes channel means for receiving the tines offork-lift equipment.
 7. A collector as claimed in claim 1 wherein: saidvertical channel exit bottom end and said air filter chamber lower inletend include means for communicating the airstream at said lower end ofsaid vertical channel in a direction reversal flow from downwardlydirectly out of said channel to immediately upwardly as said airstreamis received into said air filter chamber.
 8. A collector as set forth inclaim 1 wherein: said blower means includes positive displacement blowermeans.
 9. A collector as set forth in claim 1 further including: switchmeans for automatically shutting off said blower means upon the fillingof said hopper with collected particulate material.
 10. A portable,heavy-duty three stage vacuum collector apparatus for the sequentialremoval of heavier, residual, and most finely divided airbornparticulate material from an airstream, said collector comprising: aplatform base; a material collection hopper; means for mounting saidbase in airtight relation atop said material collection hopper; blowermeans on said base; a cyclone separator first stage mounted on saidbase, said first stage including, a. inlet and outlet ports forrespectively receiving a stream of air and airborn particulate material,and withdrawing an exhaust stream of air, and b. means, in opencommunication through said base, for substantially separating saidheavier particulate material from said stream and directing said heaviermaterial into said collector hopper; a particulate material acceleratorsecond stage mounted on said base immediately adjacent said cycloneseparator first stage, said second stage including, a. a verticallyextending nozzle means having one end communicating with said outletport for receiving said airstream and accelerating said particulatematerial in said airstream, b. chamber means vertically disposed belowsaid nozzle means, for receiving said airstream and particulate materialaccelerated by said nozzle means, c. orifice means at the top end ofsaid chamber means, disposed beneath said nozzle means, for permittingentry into said chamber means from said nozzle means of said airstreamand particulate material accelerated by said nozzle means, andpermitting exit of said airstream from said chamber means; d. means atthe bottom end of said chamber means, in communication through saidbase, for substantially separating said residual particulate materialfrom the exhaust stream of said cyclone separator first stage anddirecting it toward said collection hopper, e. closure means associatedwith said last recited separating and directing means, f. means mountingsaid closure means for movement between an open position, which permitspassage of said separated residual particulate material into saidcollection hopper, and a closed position in which such passage isprevented, and g. means, responsive to operation of said blower, forurging said closure means to said closed position when said blower isblowing and to said open position when said blower is not blowing; avertical channel having an upper end thereof for receiving saidairstream exiting from said orifice means, including means for directingsaid airstream downwardly within said vertical channel toward an exitbottom end thereof; an air permeable particulate material-entrappingthird stage mounted on said base immediately adjacent said particulatematerial accelerator second stage, said third stage including, a. an airfilter chamber having a lower air inlet end and an upper air exhaustend; b. a filter element mounted in said filter chamber; c. meanscommunicating said vertical chamber bottom end to the lower air inletend of said filter chamber for receiving said airstream from saidvertical channel bottom end exit; d. means at the bottom end of saidfilter chamber, in communication through said base, for substantiallyseparating the most finely divided of said particulate material from theexhaust stream of said particulate material accelerator second stage anddirecting said separated particulate material toward said collectionhopper; e. closure means associated with said last-recited separatingand directing means, f. means mounting said closure means for movementbetween an open position, which permits passage of said separated mostfinely divided particulate material into said collection hopper, and aclosed position in which such passage is prevented, and g. means,responsive to operation of said blower, for urging said closure means tosaid closed position when said blower is blowing and to said openposition when said blower is not blowing, said blower means being incommunication with said first, second and third stages for drawing intosaid first stage a stream of air and airborn particulate material andexhausting from said third stage a stream of air from which saidparticulate material has been substantially separated.
 11. Collectorapparatus as set forth in claim 10 wherein said platform base includeschannel means for receiving the tines of fork-lift equipment.